From 01f18af98b04dc3f47c37a150ae342fafd7337df Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Fri, 24 Aug 2018 13:17:49 +0100 Subject: hw/display/bcm2835_fb: Fix handling of virtual framebuffer The raspi framebuffir in bcm2835_fb supports the definition of a virtual "viewport", which is smaller than the full physical framebuffer size and at an adjustable offset within it. Only the viewport area is sent to the screen. This allows the guest to do things like double buffering, or scrolling by adjusting the viewport origin. Currently QEMU doesn't implement this at all. Add support for this feature: * the property mailbox code needs to distinguish the virtual width/height from the physical width/height * the framebuffer code needs to do something with the virtual width/height/origin information Note that the wiki documentation on the semantics of the virtual and physical height and width has it the wrong way around -- the virtual size is the size of the allocated buffer, and the physical size is the size of the display, so the virtual size is always the same as or larger than the physical. If the viewport size is set smaller than the physical screen size, we ignore the viewport settings completely and just display the physical screen area. Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson Message-id: 20180814144436.679-7-peter.maydell@linaro.org --- include/hw/display/bcm2835_fb.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/hw/display/bcm2835_fb.h b/include/hw/display/bcm2835_fb.h index 95bcec7..d992c60 100644 --- a/include/hw/display/bcm2835_fb.h +++ b/include/hw/display/bcm2835_fb.h @@ -62,7 +62,8 @@ void bcm2835_fb_reconfigure(BCM2835FBState *s, BCM2835FBConfig *newconfig); */ static inline uint32_t bcm2835_fb_get_pitch(BCM2835FBConfig *config) { - return config->xres * (config->bpp >> 3); + uint32_t xres = MAX(config->xres, config->xres_virtual); + return xres * (config->bpp >> 3); } /** @@ -71,7 +72,8 @@ static inline uint32_t bcm2835_fb_get_pitch(BCM2835FBConfig *config) */ static inline uint32_t bcm2835_fb_get_size(BCM2835FBConfig *config) { - return config->yres * bcm2835_fb_get_pitch(config); + uint32_t yres = MAX(config->yres, config->yres_virtual); + return yres * bcm2835_fb_get_pitch(config); } #endif -- cgit v1.1